SCIENCE NOTES
Random Shit that nori wants to study (MAY NOT BE HELPFUL) Dispersion-the action of distributing things or people over a wide area Triangular prism-a prism whos bases are triangles Visible Spectrum-the distriution of colours produced when light is dispersed by a prism Scattering-what happens as light hits a hard surface Primary rainbow-the most common of the rainbows formed by lighting hitting a raindrop Primary colours-any of a group of colours from which all other colours can be obtained Secondary colours-a colour resulting from the mixing of two primary colours Filter-a porous device for removing impurities or solid particles There are two types of lenses Concave Curves inwards and are thinner in the middle, also called diverging lens as rays spread out Convex Convex-curves outwards And are fatter in the middle aslos called converging lens as the light rays meet at the point of focus Refraction is the bending of light rays as it passes from one substance eto another of different density As light enters different mediums. The speed also changes for e.g. as light enters the glass its speed is reduced from 300000km/sec to 200000km/sec Light is a type of electromagnetic wave, it can travel through vacum as well as sold liquid and gas. Travels at 300 000km per sec If most of the light travels through a substance the surface is called transparent Translucent:it will allow very little light to pass through Opaque: Will not let light through Luminous: objects How light travels Light travels in a straight line and is absorbed or reflected when it hits a opaque surface, It is refracted or bent or it passes form one transparent substance to another It is scattered when it passes through a translucent object or is reflected from a rough surface Galileo was the first person to use a telescope to study the planets and stars Today astronomers use very sophisticated: telescopes, computers and space probes to study space TELESCOPES Instruments that collects radition from distant objects and converts it to a picture or uses it to analyses the object Each object of radition is detected by its own special designed telescopes Optical telescopes: these collect and detect light coming from objects(planets and stars) and magnifies the image. These uses wither mirrors (reflecting telescope), lenses (refracting telescopes) or a combination of mirrors or lenses #Refracting telescopes: these use lenses. Light rays from an object pass through a lens at the front of the telescope. This lends bends the rays to form an image. The eyepiece lens at the other end of the telescope passes this image into the eye #Disadvantages: More expensive, more problems #Advantages: Not as much maintanence as relecting telescopes, 2.Reflecting telescope: these uses mirrors . A concave mirror at the end reflects light rays so that they meet and a flat mirror then reflects these rays into the eyepiece Disadvantage: Needs a lot of maintance, breaks when it is roughly handed Radio telescope: These consist of a large dish that collects radio waves, which is reflected onto a small aerial tuned to a particular wavelenght . THE SIGNALS ARE AMPLFIED AND PASSED to a reciever in the control room Hublle space telescope: This is a reflecting telescope oriting the EARTH AND IS 50 TIMES MORE SENSITIVE THAN GROUND BASED TELESCOPE *Open Universe *If the universe has a low enough mass, it will keep on expanding but at a decreasing rate *Eventually the stars and galaxies would cease to shine and it would be a dark and cold place *Closed Universe *Flat universe *States that the universe will eventally stop expanding but never reverse *Accelerating universe *Expansion of universe is happening more and more rapidly due to cosmological force called as 'dark energy' that overrides gravity *Black holes *If a massive star collapses to form a black hole-an object so dense that anything close by will be drawn into its overpowering gravity. *Pulsars *Rapidly rotating neutron with a strong magnetic field *It emits radio waves that sweeps across space as it rotates *Quasars *Bright cones of distant violent galaxies that emit huge amounts of energy in jet streams of radio waves *Neutron star *Dense objects forming after a supernova occur *After explosion core collapses under their own gravity forcing electrons into the nucleus of the atoms,forming particles called neutrons The point of singularity is when the Big Bang started. Ting spec of light containing infinite energy of density and burst out creating space as it travelled(universe expanded in all directions The point of singularity-energy converted to matter and antimatter- universe expands to become 100 million billion billion times bigger(100 trillion trillion Celsius)-matter and antimatter collide release energy called photin-1sec-10 billion celsius-3min-1 billion Celsius quarks clump to from protons and neutrons H-HE-h-300000yrs- radiation clears atomic nuclei combine with electrons to form 77%H and 23% He elements- H and he clump to force of gravity-clump forms galaxies- H atoms fused to form stars-planets and other heavenly bodies-our solar system-chemistry of life Scientists have proposed the idea that the universe is expanding *This was proposed by the concept of the Doppler Effect- noticed with the change in sound pitch from high to low as the sound passes *The change in wavelength and pitch is known as the Doppler Effect after Christian Doppler. LIGHT WAVE *The visible light waves emitted from a star act the same way as sound waves. *Fast moving light sources such as stars and galaxies emit range of different light waves of various colour which we call the spectrum of colours. This can be observed using a spectrometer *If a star is moving away from us as we observed it from Earth, the wavelength gets longer and if its moving towards us then the wavelength gets shorter IF A STAR IS MOVING TOWARDS US IT HAS LONGER WAVELENGTH AND IS BLUE AND GOES AWAY IS RED Category:Homework